A compound useful as an
AMPK-activating agent is provided. A compound represented by formula (I) (wherein X represents a substituted or unsubstituted
alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted
aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted cycloalkenyl group or a substituted or unsubstituted heterocyclyl group; R1 represents a
hydrogen atom, a
halogen atom, a cyano group, a nitro group, a carboxy group, a substituted or unsubstituted
alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted
acyl group, a substituted or unsubstituted carbamoyl group, a substituted or unsubstituted alkylthio group, a substituted or unsubstituted alkylsulfinyl group, a substituted or unsubstituted alkylsulfonyl group or a substituted or unsubstituted alkyloxycarbonyl group; R2 represents a
halogen atom, a substituted or unsubstituted
alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted
aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted cycloalkenyl group, a substituted or unsubstituted heterocyclyl group or the like; R3 represents a
halogen atom, a
hydroxy group, a cyano group, a nitro group, a carboxy group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted
aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted cycloalkenyl group, a substituted or unsubstituted heterocyclyl group or the like; and R4 represents a
hydrogen atom, a halogen atom, a
hydroxy group, a cyano group, a nitro group, a carboxy group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group or the like) or a pharmaceutically acceptable salt thereof.